User`s guide

Creating the Correction Factor
As you have seen in this section, the Vector Header record and its associated Channel Header records
contain all the information you need to create a correction factor for a trace’s Y-axis data. Just complete
the following steps:
1. Determine which channels were used to gather data for the trace. (Look at the Vector Header
record’s the_CHANNEL_record fields.)
2. Determine which window correction factor (if any) was used for each channel. (Look in the
Channel Header record’s SDF_WINDOW structure; the field is windowCorrMode.)
3. Create a combined correction factor for each channel using the following formula:



window correction
EU correction



pwrOfChan ⁄ 48
window correction is equal to 1 if step 2 indicates that no window correction was used, otherwise it
is the value of either narrowBandCorr or wideBandCorr.
EU correction is the value of int2engrUnit.
4. Create a trace correction factor by multiplying the two channel correction factors.
Now you can correct the Y-axis data. Just multiply each Y-axis value by the trace correction factor.
Note Some traces are created with data from just one channel. (To indicate that only one
channel was used, one “the_CHANNEL_record” field contains a value of −1.) For
traces such as these, the combined correction factor for the single channel is also your
trace correction factor.
Standard Data Format (SDF)
B-33